A typical blender or food processor includes a container, often in the form of a pitcher having a handle and a spout, into which food items to be blended or mixed are placed. Then a cover or lid is positioned on the container so that the contents thereof cannot escape during the blending process. That process includes the high speed rotation of a blade or blades positioned near the bottom of the container which induces a circulation of the contents of the container. Such action often creates a pressure build-up within the container, particularly if the container is quite full, which can blow the lid off the container and allow the contents thereof to escape. Such can present a safety problem, particularly if the contents of the container are hot.
In addition, many lids for blender containers are provided with a central opening so that additional food items can be added to the container as may be necessary during the blending process. This opening also allows the user to manually agitate or mix the contents of the container during the blending process should that be necessary. When access to the contents of the container is not necessary, typically a plug is inserted into the central opening to seal the container. However, these plugs are normally maintained in the opening only by a friction fit, and in the circumstances of pressure build-up previously described, the plugs can easily blow out of the lid even if the lid remains on the container, resulting in the potential escape of the contents from the container.
The need exists, therefore, for a system which securely attaches a lid to the container of a blender and securely attaches a plug to a lid having an opening therein.